The invention relates to a pipe coupling, comprising coupling halves which are situated at pipe ends, namely a connector and a socket end.
In order to connect and disconnect media conducting pipes, hoses or the like, nowadays flat sealing couplings with a low amount of leakage oil, also called flat face couplings, are increasingly used which comprise two coupling halves which can be plugged into one another, a connector and a socket end. Flat face coupling halves are distinguished by in each case flat end sides which can be cleaned easily before a coupling operation; moreover, they have a low amount of leakage oil, since no oil has to be routed into the open during coupling or in the case of disconnecting.
Coupling halves can be pushed into one another and held manually or by means of apparatuses, such as by screw connections, plug connections having snap-action closures, eccentric drives, media-loaded cylinder/piston units or the like.
When the pipe ends with their coupling halves which are situated on them are pushed into one another, the overall pipe length is disadvantageously shortened by the push-in distance, which entails a reduction in the original pipe volume and therefore requires a necessary compression of contained media.
If media which can be compressed only with difficulty or have already been pressurized are situated in the pipes, such as water or oil, the pipe coupling operation requires a very large amount of force. A pipe connection often cannot be produced because the available push-in force of the coupling apparatuses is not sufficient to provide the necessary force for media compression.
These coupling problems are often solved on construction site vehicles by an unpermitted discharge of excess oil from pipelines into the environment, which cannot be tolerated in fact.
Recently, there have been technical attempted solutions, such as a coupling connector which is described in DE-U 202006014061.1, which attempt to split the described overall, necessary pipe shortening during pipe connection into a first region which is as large as possible of an easily possible air compression and into a remaining region which is as small as possible of a fluid compression.
As has been shown in practice, although it is made easier to achieve the necessary media compression, it is still not sufficient for operation without problems. Specifically in the case of pipes having a large volume, this volume-split media compression cannot be achieved with conventional push-in apparatuses.
A further conventional attempted solution, likewise to be seen in DE-U 202006014061.1, comprises it being possible for media pressure to escape from the connector side into the socket end side by means of a small pressure relief valve which opens during the split compression travel, and for it to be possible for any differing media pressures to be thus reduced in an equalizing manner.
This aid also alleviates the problems during the connection of coupling halves only in a limited and very restricted manner.